Aerosol dispensers are well known in the art. Aerosol dispensers typically comprise an outer container which acts as a frame for the remaining components and as a pressure vessel for propellant and product contained therein. Outer containers made of metal are well known in the art. However, metal containers can be undesirable due to high cost and limited recyclability.
The outer containers are typically, but not necessarily, cylindrical. The outer container may comprise a bottom for resting on horizontal surfaces such as shelves, countertops, tables etc. The bottom of the outer container may comprise a re-entrant portion as shown in U.S. Pat. No. 3,403,804. Sidewalls defining the shape of the outer container extend upwardly from the bottom to an open top.
The open top defines a neck for receiving additional components of the aerosol dispenser. The industry has generally settled upon a neck diameter of 2.54 cm, for standardization of components among various manufacturers, although smaller diameters, such as 20 mm, are also used. Various neck shapes are shown in US 2007/02782531 A1; U.S. Pat. Nos. 7,303,087; 7,028,866; and commonly assigned U.S. Pat. No. 6,019,252.
Typically a valve cup is inserted into the neck. The valve cup is sealed against the neck to prevent the escape of the propellant and loss of pressurization. The valve cup holds the valve components which are movable in relationship to the balance of the aerosol dispenser.
Aerosol dispensers, having a valve cup and movable valve components, may comprise different embodiments for holding, storing, and dispensing product used by the consumer. In one embodiment, the product and propellant are intermixed. When the user actuates the valve, the product and propellant are dispensed together. This embodiment may utilize a dip tube. The dip tube takes the product and propellant mixture from the bottom of the outer container. By dispensing from the bottom of the outer container, the user is more likely to achieve dispensing of the product/propellant mixture and not dispense pure propellant from the headspace. This embodiment may be used, for example, to dispense shaving cream foams.
The dip tube embodiment of an aerosol dispenser has the disadvantage that when the user tips the aerosol dispenser from a vertical orientation, dispensing of gas from the headspace, rather than dispensing of product/propellant mixture, may occur. This disadvantage may occur when the aerosol dispenser contains a product such as a body spray, which the user dispenses all over his/her body, often from inverted positions.
To overcome this disadvantage, other embodiments could be utilized. For example, a collapsible, flexible bag may be sealed to the opening on the underside of the valve cup or may be placed between the valve cup and the container. This bag limits or even prevents intermixing of the contents of the bag and the components outside of the bag. Thus, product may be contained in the bag. Propellant may be disposed between the outside of the bag and the inside of the outer container. Upon actuation of the valve, a flow path out of the bag is created. Gage pressure from the propellant disposed between the bag and the outer container causes pressurization of the product, forcing the product to flow into ambient pressure. This embodiment is commonly called a bag on valve and may be used, for example, in dispensing shaving cream gels. In either embodiment, flow to the ambient may comprise droplets, as used for air fresheners or may comprise deposition on a target surface, as may occur with cleansers.
The process for manufacturing a bag on valve type aerosol dispenser is complicated. One the filling operation is used to pressurize the outer container with propellant. This filling operation may utilize hydrocarbon propellant and/or inert gas propellant, such as Tetrafluoroprop-1-ene commercially available from Honeywell Company of Morristown, N.J.
Specialized equipment is typically used for pressurizing the outer container with the various propellant gases. If a hydrocarbon propellant is selected, the manufacturing process becomes more complex and costly due to safety concerns, environmental regulations and other industry regulations.
Propellant filling of aerosol dispensers presents its own challenges. Propellant must be added to the outer container, without contaminating the inside of the bag, if present. Further, leakage to the ambient must be minimized. And the relevant portions of the aerosol container must be sealed in a manner to prevent later leakage and depressurization after shipment, handling and storage.
Yet different equipment must be utilized for disposing the desired product into the bag. Often, the outer container pressurization and disposing of product inside the bag occur in two separate operations at the same location. This manufacturing process is influenced by industry regulations governing transport, storage and shipping of pressure vessels, such as an aerosol dispenser. Thus, to avoid extra shipping operations, the pressurization step and product filling step often occur at the same site.
However, utilizing a common site for pressurization and filling of the aerosol dispenser presents certain problems and inherent fixed costs. For example, each manufacturing site must have the complex and highly regulated propellant pressurizing equipment and safety systems. Yet, multiple manufacturing sites may be desirable if the product is to be shipped to several geographies.
Conversely, if a single manufacturing site is used to source multiple geographies, that site must be knowledgeable in specific products and consumer preferences for each geography. Some of the geographies may be remote. A single manufacturing site may not be able to quickly respond to changes in consumer preference or to tailor the product to the unique consumer preferences in different geographies. Different geographies may further have different labeling requirements and languages. Additionally, import duties and taxes for finished products are typically higher than the duties and taxes for intermediates exported to that same country.
Thus, limiting complex manufacturing to fewer sites/first regions, then exporting a product to a second region for completing the manufacturing process may be viable. Such manufacturing may provide cost benefits for the product and convenient customization of the product for the second region.